import os
from telegram import Update
from telegram.ext import Application, CommandHandler, ContextTypes, MessageHandler, filters


async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    assert update.effective_message
    await update.effective_message.reply_text("Hi! Send me any text.")


async def echo(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    assert update.effective_message and update.effective_message.text
    await update.effective_message.reply_text(update.effective_message.text)


def main() -> None:
    token = os.environ["TELEGRAM_BOT_TOKEN"]
    app = Application.builder().token(token).build()
    app.add_handler(CommandHandler("start", start))
    app.add_handler(MessageHandler(filters.TEXT & ~filters.COMMAND, echo))
    app.run_polling(allowed_updates=Update.ALL_TYPES)


if __name__ == "__main__":
    main()

import json
import os
import urllib.parse
import urllib.request

TOKEN = os.environ["TELEGRAM_BOT_TOKEN"]
API = f"https://api.telegram.org/bot{TOKEN}"


def call(method: str, **params):
    data = urllib.parse.urlencode(params).encode()
    with urllib.request.urlopen(f"{API}/{method}", data=data, timeout=60) as resp:
        return json.loads(resp.read().decode())


def main() -> None:
    offset = 0
    while True:
        payload = call("getUpdates", offset=offset, timeout=30)
        for upd in payload.get("result", []):
            offset = upd["update_id"] + 1
            msg = upd.get("message") or {}
            text = msg.get("text")
            chat = msg.get("chat") or {}
            chat_id = chat.get("id")
            if text and chat_id:
                call("sendMessage", chat_id=chat_id, text=f"echo: {text}")


if __name__ == "__main__":
    main()

set TELEGRAM_BOT_TOKEN=123456:ABC...
python bot.py